Palindromic Concatenation

Given two strings s₁ and s₂, determine if the concatenation of these two strings can be rearranged to form a palindrome. A palindrome is a string that reads the same forward and backward. A necessary and sufficient condition for a string to be rearranged into a palindrome is that at most one character has an odd frequency. In mathematical terms, if we let \( f(c) \) be the frequency of character \( c \) in the concatenated string \( s = s_1 + s_2 \), then \( s \) can be rearranged into a palindrome if and only if

[ \sum_{c} \mathbf{1}_{{f(c) \text{ is odd}}} \le 1. ]

Your task is to implement a program that reads multiple test cases from standard input, processes each one according to the above rule, and outputs "YES" if the concatenation can form a palindrome and "NO" if it cannot.

inputFormat

The input is read from standard input. The first line contains an integer T representing the number of test cases. Each test case consists of two subsequent lines:

• The first line contains the string s₁.
• The second line contains the string s₂.

Both strings contain only lowercase English letters.

outputFormat

For each test case, output a single line to standard output containing either "YES" if it is possible to rearrange the concatenation of s₁ and s₂ to form a palindrome, or "NO" otherwise.

## sample

3
aabb
ccdd
abc
def
ab
ba

YES
NO
YES

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